JP4472990B2 - Reflective liquid crystal display device and manufacturing method thereof - Google Patents

Description

  The present invention relates to a liquid crystal display device and a method for manufacturing the same, and more particularly, a reflective liquid crystal display device capable of preventing a battery effect when a pad electrode made of a transparent conductive film is applied and a method for manufacturing the same. It is about the method.

  In today's information era, the role of electronic display devices as information transmission devices becomes increasingly important, and various electronic display devices are widely used in various industrial household electric appliances. These electronic display devices are continuously improved by adding new functions to meet various demands of the information society.

  In general, an electronic display device refers to a device that transmits various information to a person who uses the information through vision. That is, an electronic display device can be defined as an electronic device that converts electrical information signals output from various electronic devices into optical information signals that can be recognized by human vision.

  Such an electronic display device is divided into a light-emitting display device and a light-receiving display device. The light-emitting display device displays an optical information signal by a light emission phenomenon. Display information signals. The light emitting display device includes a cathode ray tube (CRT), a plasma display panel (PDP), a light emitting diode (LED), and an electroluminescent display (ELD). The light-emitting display device is called an active display device. The light-receiving display device which is a passive display device includes a liquid crystal display device (LCD), an electrochemical display device (ECD), and an electrophoretic display device (EPID).

  Cathode ray tubes (CRTs) that have been used for a long time in image display devices such as televisions and computer monitors have high display quality and low cost, but they have disadvantages such as heavy weight, large volume and high power consumption. Have.

  However, there is a rapidly increasing demand for an electronic display device suitable for a new environment, that is, a flat panel display device having features of low driving voltage and low power consumption while being thin and light. Such a flat panel display device can be easily manufactured by rapid progress in semiconductor technology.

  However, among the various flat panel display devices developed at present, the liquid crystal display device is thinner than other display devices, and has low power consumption, low driving voltage and ease of manufacture. It is possible to display an image close to that of a wide variety of electronic devices.

  A liquid crystal display device is a transmissive liquid crystal display device that displays an image using a light source such as a backlight, a reflective liquid crystal display device that uses external natural light, and a display in a dark place where there is no indoor or external light source. It can be classified into a reflection-transmission type liquid crystal display device that operates in a transmissive display mode for displaying using an internal light source of the element and operates in a reflective display mode for reflecting outside incident light and displaying outside.

  Currently, a thin film transistor liquid crystal display (TFT-LCD) is mainly used. The thin film transistor liquid crystal display device includes a thin film transistor (TFT) in which each electrode is formed on two substrates and a voltage applied to each electrode is switched. It is common to form one. Liquid crystal display devices are classified into an amorphous type and a polycrystalline type.

  1a and 1b are sectional views of a reflection type liquid crystal display device according to a conventional method. 1A and 1B illustrate a reflective amorphous silicon thin film transistor liquid crystal display having a lower gate structure. In FIG. 1b, P indicates a pad area, D indicates a display area, and B indicates a boundary region between the pad area and the display area.

  Referring to FIGS. 1a and 1b, a chromium (Cr) film 11 and an aluminum neodymium (AlNd) film 12 are gradually deposited on a substrate 10 made of an insulating material such as glass, quartz, or sapphire, and are then photophosphorylated. A gate wiring is formed by patterning in a lithography process. The gate line includes a gate line 13 extending in a first direction, a gate electrode 12 of a thin film transistor branched from the gate line 13, and a gate terminal 15 connected to an end of the gate line 13.

  A gate insulating film 16 made of silicon nitride is deposited on the substrate 10 on which the gate wiring is formed, and an amorphous silicon film and an n + -doped amorphous silicon film are sequentially deposited thereon. Subsequently, the n + -doped amorphous silicon film and the amorphous silicon film are continuously patterned in a photolinography process to form an active pattern 17 composed of an amorphous silicon film and an n + -doped amorphous film. An ohmic contact pattern 18 composed of a silicon film is formed.

  For example, chromium (Cr) is deposited on the ohmic contact pattern 18 and the gate insulating film 16 as a second metal film, and is patterned by a photolithography process to form data wiring. The data wiring includes a data line 19 extending in a second direction orthogonal to the first direction, a source electrode 20 and a drain electrode 21 branched from the data line 19, and data connected to an end of the data line 19. A terminal 22 is included. Subsequently, the ohmic contact pattern 18 exposed between the source electrode 20 and the drain electrode 21 is dry-etched to complete a thin film transistor.

  After forming the inorganic protective film 24 made of silicon nitride on the data wiring and gate insulating film 16, the inorganic protective film 24 on the drain electrode 21 is removed. At this time, a first pad contact hole 25 and a second pad contact hole 26 for exposing the gate terminal 15 and the data terminal 22 are formed.

  After forming an organic protective film 26 made of an organic material on the entire surface of the resultant product, the drain electrode 22 and the organic protective film 26 in the pad region are removed in an exposure and development process to expose the drain electrode 22. Form. At the same time, a large number of irregularities 30 for light scattering are formed on the surface of the organic protective film 26.

  After depositing a reflective film formed of a metal having a high reflectance such as aluminum neodymium (AlNd) on the entire surface of the resultant product, the reflective film is patterned in a photolinography process, and a drain electrode is formed through the contact hole 29. A reflective electrode 32 connected to the first electrode 21 is formed. At the same time, the gate terminal 15 is connected to the gate terminal 15 through the first pad contact hole 25 and is connected to the data terminal 22 through the second pad contact hole 26 and the gate pad electrode 33 for applying a scanning voltage to the gate electrode 14. A data pad electrode 34 for applying a signal voltage to the electrode 20 is formed.

  According to the above-described conventional reflective liquid crystal display device, when the reflective electrode 32 made of an aluminum alloy such as aluminum neodymium is formed, the pad electrodes 33 and 34 are simultaneously formed. Accordingly, after a subsequent COG (chip on glass) bonding process, that is, a process of directly mounting the integrated circuit on the substrate of the LCD panel, a COG block defect occurs due to aluminum corrosion.

  Accordingly, a method of forming a pad electrode using indium tin oxide (hereinafter referred to as ITO) used for a transparent electrode has been proposed.

  FIG. 2 is a cross-sectional view of a reflective liquid crystal display device according to another conventional method. Here, P indicates a pad area, D indicates a display area, and B indicates a boundary area between the pad area and the display area.

  Referring to FIG. 2, a chromium film 51 and an aluminum neodymium (AlNd) film 52 are gradually deposited on an insulating substrate 50 such as glass, and the gate line 53 extends in a first direction by patterning by photolithography. A gate wiring including a gate electrode (not shown) branched from the gate line 53 and a gate terminal 54 connected to an end of the gate line 53 is formed.

  A gate insulating film 55 made of silicon nitride is formed on the substrate on which the gate wiring is formed, and an active pattern (not shown) made of amorphous silicon and an n + doped amorphous material are formed thereon. An ohmic contact pattern (not shown) made of quality silicon is formed.

  For example, chromium (Cr) is vapor-deposited as a second metal film on the ohmic contact pattern and the gate insulating film 55 and is patterned by a photolithography process to extend in a second direction orthogonal to the first direction. A data line including a line 56, a source branched from the data line 56, a drain electrode (not shown), and a data terminal 58 connected to an end of the data line 56 is formed. Subsequently, the ohmic contact pattern exposed between the source electrode and the drain electrode is dry-etched.

  After forming the inorganic protective film 60 made of an inorganic material on the data wiring and gate insulating film 55, the first protective film 60 on the drain electrode is removed by a photolithography process. At this time, a first pad contact hole 61 and a second pad contact hole 62 are formed to expose the gate terminal 54 and the data terminal 58, respectively. In general, ITO and Al cannot be brought into direct contact due to a galvanic corrosion phenomenon. Accordingly, the entire surface of the aluminum neodymium (AlNd) film 52 of the gate terminal 54 exposed in the process of forming the pad contact holes 61 and 62 is etched by a wet etching process. Then, the ITO pad electrode formed in the subsequent process comes into contact with the chromium film 51 of the gate terminal 54. However, when the entire surface of the aluminum neodymium film 52 exposed through the first pad contact hole 61 is etched, the side surfaces of the aluminum neodymium film 52 are also etched together due to the isotropic characteristics of the wet etching. 64 is generated.

  After depositing ITO on the pad contact holes 61 and 62 and the inorganic protective layer 60, the ITO is deposited in a photolithography process and connected to the gate terminal 54 and the data terminal 58 through the first pad contact holes 61 and 62, respectively. A gate pad electrode 65 and a data pad electrode 66 are formed. At this time, the step coverage of the gate pad electrode 65 is weak at the stepped portion in the first pad contact hole 61, that is, at the portion A where the undercut 64 is formed.

  Subsequently, an organic protective layer 68 made of an organic material is applied on the pad electrodes 65 and 66 and the inorganic protective layer 60, and then the drain electrode and the organic protective layer 68 in the pad region are patterned by exposure and development processes. A contact hole (not shown) for exposing the drain electrode is formed, and at the same time, a large number of irregularities 69 are formed on the surface of the organic protective film in the display region.

  A barrier metal layer 70 made of molybdenum tungsten (MoW) and a reflective film made of aluminum neodymium (AlNd) are sequentially stacked on the contact hole and the organic protective film 68, and then the reflective film and The barrier metal layer 70 is patterned to form a reflective electrode 72 connected to the drain electrode through the contact hole.

  According to the above-described conventional method, in order to prevent the current state of galvanic corrosion between ITO and Al, when the pad contact holes 61 and 62 are formed, the entire surface of the aluminum neodymium film 52 of the gate terminal 54 is wet etched. Since the etching is performed, an undercut 64 is generated in the aluminum neodymium film 52.

  In addition, after the pad electrodes 65 and 66 are formed, two photolithography processes for forming the organic protective film 68 and the reflective electrode 72 are performed, and the pixel contact characteristics are improved before the reflective electrode 72 is formed. Therefore, an etching process using an aluminum etchant is added. As a result, a chemical (chemical) such as a phenomenon solution or an etchant permeates through a portion (see A in FIG. 2) where a step is formed in the first pad contact hole 61 in the course of the above-described process, and the aluminum neodymium film 52 is formed. Will erode. In addition, since such a chemical acts as an electrolyte and induces a battery effect between aluminum and ITO, there is a problem that the gate pad electrode 61 is lifted.

  Accordingly, the present invention has been devised to solve the problems of the conventional method performed previously, and one object of the present invention is to provide a battery reaction when a pad electrode made of a transparent conductive film is applied. An object of the present invention is to provide a reflective liquid crystal display device that can be prevented.

  Another object of the present invention is to provide a manufacturing method of a reflective liquid crystal display device capable of preventing a battery reaction when a pad electrode composed of a transparent conductive film is applied.

In order to achieve the above-described object of the present invention, the present invention includes a substrate including a display region and a pad region positioned outside the display region, and a wiring layer terminal positioned in the pad region. A wiring layer formed of a first metal film and a second metal film laminated thereon, the second metal film being made of aluminum or an aluminum alloy, and the substrate and the wiring layer A first protective film having a pad contact hole formed on the wiring layer terminal and exposing the first metal film in a portion of the wiring layer connected to the wiring layer terminal and the wiring layer terminal; and the second protective film in the pad contact hole. in a state where the metal film is not laminated on the first metal layer, wherein the side wall and the bottom surface of the pad contact hole, and continuously formed on a portion of said first protective layer, the wiring layer terminals and the wiring A pad electrode formed of a transparent conductive film connected to a first metal film of a portion of the wiring layer connected to the terminal; a second protective film formed in a region on the substrate excluding the pad region; A reflective electrode formed on the second protective film in the display region, and the pad contact hole is extended to a lower portion of the second protective film in a boundary region between the display region and the pad region. Provided is a reflection type liquid crystal display device formed.

Another object of the present invention is to provide a substrate including a display region and a pad region located outside the display region, and a first metal film and a second metal film made of aluminum or an aluminum alloy on the substrate. Are sequentially stacked, gate lines extending in the first direction, gate lines formed in the pad region and including terminals connected to ends of the gate lines, and formed on the gate lines and the substrate. A gate insulating film; a data line formed on the gate insulating film and extending in a second direction perpendicular to the first direction; a data terminal formed in the pad region and connected to an end of the data line; And a data line formed on the data line and the gate insulating film, the gate line penetrating the gate insulating film and connected to the gate terminal and the gate terminal. Of the first protective layer having a first pad contact hole exposing the first metal film portion, in a state in which the second metal film in the pad contact hole is not laminated on the first metal layer, said first A transparent conductive layer formed continuously on a side wall and a bottom surface of a pad contact hole and a part of the first protective film and connected to a first metal film of a part of a date line connected to the gate terminal and the gate wiring. A gate pad electrode made of a film; a second protective film formed in a region excluding the pad region on the substrate; and a reflective electrode formed on the second protective film in the display region. According to another aspect of the present invention, there is provided a reflective liquid crystal display device, wherein the first pad contact hole is extended to a lower portion of a second protective film in a boundary region between the display region and the pad region. It can be achieved to.

In order to achieve the above-described object of the present invention, the present invention includes a wiring layer terminal positioned in the pad area on a substrate including a display area and a pad area positioned outside the display area, and includes a first metal. and film, a second metal film laminated thereon, forming an aluminum or a wiring layer formed of a second metal film made of aluminum alloy, the said substrate and the wiring layer Forming a wiring layer terminal and a first protective film having a pad contact hole exposing the first metal film in a portion of the wiring layer connected to the wiring layer terminal; and covering the entire surface of the second metal film in the pad contact hole. Removing by etching, continuously forming a pad electrode made of a transparent conductive film on the side wall and bottom surface of the pad contact hole and a part of the first protective film, Connecting a line layer terminal and a first metal film of a portion of the wiring layer connected to the wiring layer terminal; forming a second protective film in a region excluding the pad region on the substrate; And a step of forming a reflective electrode on a second protective film in a display region. A method for manufacturing a reflective liquid crystal display device is provided.

Another object of the present invention is a first metal film and a second metal film stacked on the first metal film on a substrate including a display area and a pad area located outside the display area . A gate line including a gate line formed of a second metal film made of aluminum or an aluminum alloy and extending in a first direction, and a gate terminal formed in the pad region and connected to an end of the gate line. Forming a gate insulating film on the gate wiring and the substrate; forming a data line on the gate insulating film in a second direction perpendicular to the first direction; and a pad region. Forming a data line including a data terminal formed and connected to an end of the data line; and removing the second metal film in the pad contact hole by etching the entire surface. And forming a first pad contact hole on the data line and the gate insulating film to expose the gate terminal and the first metal film of a part of the gate line connected to the gate terminal through the gate insulating film. Forming a first protective film, and forming a gate pad electrode made of a transparent conductive film continuously on a side wall and a bottom surface of the first pad contact hole and a part of the first protective film, Connecting to a first metal film of a part of a gate line connected to a terminal and the gate wiring; forming a second protective film formed in a region on the substrate excluding the pad region; And a step of forming a reflective electrode formed on the second protective film in the display region. It can be.

  According to the present invention, an open region of the first protective film, that is, a pad contact hole is formed by extending to the lower part of the second protective film in the boundary region between the display region and the pad region, and then the transparent conductive film A configured pad electrode is formed. Then, the portion where the step of the open region is made, that is, the portion where the step coverage of the pad electrode is weak is covered with the second protective film due to the undercut of the second metal film. Accordingly, by preventing the chemical from permeating through the stepped portion of the open region and inducing a battery reaction between the pad electrode and the second metal film of the wiring layer, the lifting and the second of the pad electrode can be prevented. Corrosion of the metal film can be prevented.

  When the first metal film of the wiring layer exposed through the pad contact hole is covered with the pad electrode up to the boundary region between the display region and the pad region, the first metal film of the wiring layer terminal is short-circuited in a predetermined region. In addition, an overlap with the pad electrode covering the first metal film that is not short-circuited can be formed.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  3 is a plan view of a reflective liquid crystal display device according to an embodiment of the present invention. FIGS. 4a and 4b are diagrams of the reflective liquid crystal display device taken along lines EE ′ and FF ′ of FIG. 3, respectively. As a cross-sectional view, an amorphous silicon thin film transistor liquid crystal display device having a bottom-gate structure is illustrated. Here, P indicates a pad area, D indicates a display area, and B indicates a boundary area between the pad area and the display area.

  3 to 4a and 4b, chromium (Cr), molybdenum (Mo), tantalum (Ta), titanium (Ti), etc. are formed on a substrate 100 made of an insulating material such as glass, quartz, or sapphire. A gate wiring made of a double metal film is formed by laminating the first metal film 102 and the second metal film 104 made of aluminum alloy such as aluminum (Al) or aluminum neodymium (AlNd). The gate lines are formed in the gate line 105 extended in the first direction (that is, in the lateral direction), the gate electrode 110 of the thin film transistor 195 branched from the gate line 105, and the pad region P, and the end of the gate line 115 is formed. A gate terminal 115 connected to the portion.

  A gate insulating film 120 made of an inorganic material such as silicon nitride is formed on the gate wiring and the substrate 100. An active pattern 125 made of an amorphous silicon film and an ohmic contact pattern 130 made of an n + doped amorphous silicon film are sequentially formed on the gate insulating film 120 corresponding to the gate electrode 110. .

  A data wiring made of a single metal film such as chromium (Cr) is formed on the ohmic contact pattern 130 and the gate insulating film 120. The data line is a data line 135 extended in a second direction (that is, a vertical direction) orthogonal to the data line 135, and a first electrode (hereinafter referred to as a source) that branches from the data line 135 and overlaps the first region of the active pattern 125. 140), a second electrode (hereinafter referred to as a drain electrode) 145 that overlaps a second region facing the first region of the active pattern 125, and a pad region P, and the data line 135 The data terminal 150 is connected to the end of the terminal.

  A first pad contact hole 160 exposing the gate terminal 115 and a part of the gate line 105 connected to the gate terminal 115 and a second pad contact hole 175 exposing the data terminal 150 are disposed on the data line and gate insulating layer 120. A first protective film 155 having s is formed. Preferably, the first protective layer 155 is made of an inorganic material such as silicon nitride. Specifically, the first pad contact hole 160 penetrates the first protective layer 155 and the gate insulating layer 120 to form a gate terminal 115 and a first metal layer 102 that is a part of the gate line 105 connected to the gate terminal 115. Exposed.

  A gate pad electrode 170 made of a transparent conductive film, preferably ITO, is continuously formed on the side and bottom surfaces of the first pad contact hole 160 and a portion of the first protective layer 155. The gate pad electrode 170 is connected to the gate terminal 115 and the first metal layer 102 of the gate line 105 connected to the gate terminal 115 through the first pad contact hole 160 to apply a scanning voltage to the gate electrode 110. . In addition, the data pad electrode 175 formed of the same layer as the gate pad electrode 170 is connected to the data terminal 150 through the second pad contact hole 165 and applies a signal voltage to the source electrode 140.

  A second protective layer 180 made of an organic material such as a photosensitive acrylic resin is formed on the first protective layer 155. In the display area D, which is an area where the pixel portions gather and display an image, a large number of projections and depressions 30 are formed on the surface of the second protective film 180 in order to induce light scattering and improve the reflectance. The first protective film 155 made of an inorganic material is provided to ensure the reliability of transistors and pads and improve the adhesion of COG bondering. For this reason, the second protective film 180 made of an organic material is It exists only in the area excluding the pad area P.

  A reflective electrode 185 connected to the drain electrode 145 through a contact hole 185 formed over the first protective film 155 and the second protective film 180 is formed on the second protective film 180. The reflective electrode 185 functions as a reflective plate that reflects light incident on the substrate 100 from the outside, and at the same time receives an image signal from the thin film transistor 195 formed in each pixel region of the substrate 100. It serves as a pixel electrode that generates an electric field together with a transparent electrode (not shown) of a substrate (ie, a color filter substrate). The reflective electrode 185 is formed in a pixel portion defined by the gate line 105 and the data line 135, and its end overlaps with the gate line 105 and the data line 135 in order to ensure a high aperture ratio. Although not shown, a barrier metal layer made of a metal having an etching rate similar to that of the reflective electrode 185 with respect to a predetermined etchant, preferably molybdenum tungsten (MoW), is formed below the reflective electrode 185. Can be done.

  According to the reflective liquid crystal display device of the present invention, the second protection in which the open region of the first protective film 155, that is, the first pad contact hole 160 exists in the boundary region B between the display region D and the pad region P. The film is extended to the lower part of the film 155. Then, as the process after the formation of the pad electrodes 170 and 175 progresses, the stepped region in the first pad contact hole 160, that is, the undercut 162 of the second metal film 104 causes the gate pad electrode 170. It is possible to prevent the chemical from permeating through the region where the step application property becomes weak and inducing a battery reaction between the gate pad electrode 170 and the second metal film 104. Therefore, defects such as lifting of the gate pad electrode 175 and erosion of the second metal film 104 do not occur.

  In addition, according to the reflective liquid crystal display device of the present invention, the first metal film 102 exposed through the first pad contact hole 160 is covered with the gate pad electrode 170 up to the boundary region B. Accordingly, when the chemical penetrates through the pinhole in the ITO film constituting the gate pad electrode 170 to short-circuit the first metal film 102 of the gate wiring, the gate pad electrode 170 covering the first metal film 102 that is not short-circuited. Can be formed.

  5a to 9b are cross-sectional views illustrating a method of manufacturing the reflective liquid crystal display device illustrated in FIG. Here, each figure a is a sectional view taken along line E-E 'of FIG. 3, and each figure b is a sectional view taken along line F-F' of FIG. In the drawing, P indicates a pad area, D indicates a display area, and B indicates a boundary area between the pad area and the display area.

  Referring to FIGS. 5a and 5b, a first metal film 102 and a second metal film 104 are sequentially stacked on an insulating substrate 100 such as glass, quartz, and sapphire, and then a photolithography process using a first mask. The second metal film 104 and the first metal film 102 are patterned to form a gate wiring. Preferably, the first metal film 102 is formed of about 500 liters of chromium (Cr), and the second metal film 104 is formed of about 2500 liters of aluminum neodymium (AlNd). The gate line includes a gate line 105 extending in a first direction, a gate electrode 110 of a thin film transistor branched from the gate line 105, and a gate terminal 115 connected to an end of the gate line 115.

  Referring to FIGS. 6a and 6b, an inorganic material such as silicon nitride is deposited on the gate wiring and the substrate 100 by a plasma-enhanced chemical vapor deposition (PECVD) method to a thickness of about 4500 mm. Thus, the gate insulating film 120 is formed.

  For example, an amorphous silicon film is deposited on the gate insulating film 120 as an active layer to a thickness of about 2000 mm by a PECVD method, and an ohmic contact layer is formed thereon, for example, an n + doped amorphous silicon film. Is deposited by PECVD to a thickness of about 500 mm. At this time, the active layer and the ohmic contact layer are deposited in-situ in the same chamber of the PECVD equipment. Subsequently, the film is patterned by a photolithography process using a second mask to form an active pattern 125 and an ohmic contact pattern 130 on the gate insulating film 120 above the gate electrode 110.

  Subsequently, after depositing the same metal film as chromium (Cr) on the ohmic contact pattern 130 and the gate insulating film 126 to a thickness of about 1500 to 4000 mm, the metal film is formed by a photolithography process using a third mask. Data wiring is formed by patterning. The data line includes a data line 135 orthogonal to the gate line 105, a source electrode 140 and a drain 145 branched from the data line 135, and a data terminal 150 connected to the end of the data line 135.

  Subsequently, the exposed ohmic contact pattern 130 between the source electrode 140 and the drain electrode 145 is removed by a reactive ion etching (RIE) method. Then, the thin film transistor 195 is completed on the display region D. At this time, a gate insulating layer 120 is interposed between the gate line 105 and the data line 135 to prevent the gate line 105 from contacting the data line 135.

  In this embodiment, the active pattern 125, the ohmic contact pattern 130, and the data wiring are formed using two masks. However, the present inventor reduces the number of masks used to manufacture a thin film transistor liquid crystal display device having a lower gate structure by forming an active pattern, an ohmic contact pattern, and a data wiring using a single mask. Has been filed with the Korean Patent Office as application number 1998-049710. This method will be described in detail using the same reference numerals as follows.

  First, an active layer, an ohmic contact layer, and a metal film are sequentially deposited on the gate insulating film 120. A photosensitive film is coated on the metal film, and is exposed and developed to be positioned on the channel portion of the thin film transistor. The first portion having the first thickness is positioned on the data wiring portion. A photoresist pattern (not shown) including a second portion having a thickness greater than the thickness and a third portion from which the photoresist film is completely removed is formed.

  Thereafter, the metal film under the third part, the ohmic contact layer and the active layer, the metal film under the first part, and the thickness of a part of the second part are etched to form the metal film. The data wiring, the ohmic contact pattern 130 made of an n + -doped amorphous silicon film, and the active pattern 125 made of an amorphous silicon film are simultaneously formed. Subsequently, when the remaining photoresist pattern is removed, the active pattern 125, the ohmic contact pattern 130, and the data wiring are simultaneously formed using one mask.

  Referring to FIGS. 7a and 7b, an inorganic material such as silicon nitride is deposited on the entire surface of the substrate 100 on which the thin film transistor 195 is formed to form a first passivation layer 155. The first protective layer 155 serves to ensure the reliability of the thin film transistor and the pad and to directly improve the adhesion of the circuit portion during COG bonding.

  Subsequently, a first contact hole 156 exposing the drain electrode 145 is formed by etching the first protective layer 155 and the gate insulating layer 120 in a photolithography process using a fourth mask. At the same time, a first pad contact hole 160 exposing a part of the gate terminal 115 and the gate line 105 connected to the gate terminal 115 and a second pad contact hole 175 exposing a part of the data terminal 150 are formed. . That is, the first pad contact hole 160 is formed to extend to the boundary region B between the pad region P and the display region D, while the second pad contact hole 165 is formed only in the pad region P.

  At this time, since the gate terminal 115 exposed through the first pad contact hole 160 is the second metal film 104 made of aluminum neodymium, direct contact between the ITO pad electrode formed in the subsequent process and the aluminum layer is made. In order to prevent this, the entire surface of the second metal film 104 exposed in the wet etching process using an aluminum etchant is etched. As a result, the gate terminal 115 and the first metal layer 104 in a portion of the gate line 105 connected to the gate terminal 115 are exposed through the first pad contact hole 106. Since the first metal film 102 is made of chromium, galvanic corrosion is not induced between the first metal film 102 and the ITO pad electrode formed thereon. In this way, when the second metal film 104 made of aluminum neodymium exposed through the first pad contact hole 106 is entirely etched, both sides of the second metal film 104 are etched due to the isotropic characteristics of wet etching. As a result, an undercut 162 is generated.

  Referring to FIGS. 8a and 8b, a transparent conductive layer, preferably an ITO layer, is deposited on the pad contact holes 160 and 165 and the first protective layer 155, and then the ITO is formed by a photolithography process using a fifth mask. Pattern the film. Then, the gate pad electrode 170 connected to the gate terminal 115 and the first metal film 102 in the gate line 105 connected to the gate terminal 155 through the first pad contact hole 160 is formed. At the same time, a data pad electrode 175 connected to the data terminal 150 through the second pad contact hole 165 is formed.

  Preferably, the gate pad electrode 170 extends to a boundary region B between the pad region P and the display region D in order to completely cover the first metal film 102 exposed through the first pad contact hole 160. Form. Accordingly, when chemical penetrates through the pinholes in the ITO film constituting the gate pad electrode 170 and the first metal film 102 is short-circuited, redundancy is applied to the gate pad electrode 170 covering the first metal film 102 that is not short-circuited. Can be formed.

  Referring to FIGS. 9A and 9B, an organic material having a low dielectric constant, preferably a photosensitive acrylic resin, is formed on the gate pad electrode 170, the data pad electrode 175, and the first passivation layer 155 to a thickness of about 2 μm or more. The second protective film 180 is formed by coating. Since the second protective layer 180 suppresses generation of parasitic capacitance between the second protective layer 180 and the lower data line, the pixel electrode (that is, the reflective electrode) is formed so as to overlap the gate line 105 and the data line 135 and is high. An aperture ratio thin film transistor liquid crystal display device can be realized.

  Subsequently, a sixth mask having a pattern corresponding to the contact hole 185 is formed on the second passivation layer 180 in order to form the contact hole 185 in the second passivation layer 180, and then first full. Through the exposure process, the second protective film 180 on the drain electrode 145 and the second protective film 180 in the pad region P are exposed. Subsequently, the seventh mask for microlens formation is positioned on the second protective film 180, and then the second protective film 180 in the display region D excluding the contact hole 185 through a lens exposure process using the seventh mask. Second exposure is performed. Thereafter, when a developing process is performed using a tetramethyl ammonium hydroxide (TMAH) developer, a contact hole 185 extending from the first contact hole 156 to expose the drain electrode 145 is formed in the second protective film 180. At the same time, a large number of irregularities 182 are formed. At this time, the second protective film 180 in the pad region P is removed.

  Subsequently, in order to reflow and cure the second passivation layer 180, after curing for 100 minutes at a temperature of about 130 ° C. to 230 ° C., an aluminum etchant is used to improve pixel contact characteristics. The used whole surface etching process proceeds in a few seconds.

  Thereafter, a metal having an etching rate similar to that of the reflective film, for example, molybdenum tungsten (MoW), is deposited to a thickness of about 500 mm on the etchant for etching the reflective film constituting the reflective electrode on the entire surface of the resultant product. A barrier metal layer (not shown) is formed. A reflective film having a high reflectance such as aluminum neodymium (AlNd) or silver (Ag) is deposited on the barrier metal layer to a thickness of about 1500 mm. Subsequently, the reflective film and the barrier metal layer are patterned by a photolithography process using an eighth mask to form a reflective electrode (reference numeral 190 in FIG. 4a) provided to the pixel electrode and the reflective plate. The reflective electrode 190 is connected to the drain electrode 145 of the thin film transistor.

  As described above, according to the present invention, after forming the open region of the first protective film, that is, the pad contact hole to extend below the second protective film between the display region and the pad region, the transparent conductive film A pad electrode is formed. Then, the portion where the step of the open region is made, that is, the portion where the step coverage of the pad electrode is weak is covered with the second protective film due to the undercut of the second metal film. Accordingly, by preventing the chemical from permeating through the stepped portion of the open region and inducing a battery reaction between the pad electrode and the second metal film of the wiring layer, the lifting and the second of the pad electrode can be prevented. Corrosion of the metal film can be prevented.

  The first metal film of the wiring layer exposed from the pad contact hole is covered with the pad electrode up to the boundary region between the display region and the pad region, so that the first metal film of the wiring layer terminal is removed from the predetermined region. A redundancy can be formed on the pad electrode covering the first metal film that is not short-circuited when short-circuited.

  As described above, the embodiments of the present invention have been described in detail. However, the present invention is not limited to the embodiments, and as long as it has ordinary knowledge in the technical field to which the present invention belongs, without departing from the spirit and spirit of the present invention, The present invention can be modified or changed.

It is sectional drawing of the reflection type liquid crystal display device by the conventional method. It is sectional drawing of the reflection type liquid crystal display device by the conventional method. It is sectional drawing of the reflection type liquid crystal display device by the other conventional method. 1 is a plan view of a reflective liquid crystal display device according to the present invention. FIG. 4 is a cross-sectional view of a reflective liquid crystal display device taken along lines E-E ′ and F-F ′ in FIG. 3. FIG. 4 is a cross-sectional view of a reflective liquid crystal display device taken along lines E-E ′ and F-F ′ in FIG. 3. FIG. 5 is a cross-sectional view for illustrating a method of manufacturing the reflective liquid crystal display device illustrated in FIG. 4. FIG. 5 is a cross-sectional view for illustrating a method of manufacturing the reflective liquid crystal display device illustrated in FIG. 4. FIG. 5 is a cross-sectional view for illustrating a method of manufacturing the reflective liquid crystal display device illustrated in FIG. 4. FIG. 5 is a cross-sectional view for illustrating a method of manufacturing the reflective liquid crystal display device illustrated in FIG. 4. FIG. 5 is a cross-sectional view for illustrating a method of manufacturing the reflective liquid crystal display device illustrated in FIG. 4. FIG. 5 is a cross-sectional view for illustrating a method of manufacturing the reflective liquid crystal display device illustrated in FIG. 4. FIG. 5 is a cross-sectional view for illustrating a method of manufacturing the reflective liquid crystal display device illustrated in FIG. 4. FIG. 5 is a cross-sectional view for illustrating a method of manufacturing the reflective liquid crystal display device illustrated in FIG. 4. FIG. 5 is a cross-sectional view for illustrating a method of manufacturing the reflective liquid crystal display device illustrated in FIG. 4. FIG. 5 is a cross-sectional view for illustrating a method of manufacturing the reflective liquid crystal display device illustrated in FIG. 4.

Explanation of symbols

10, 100 Substrate 11 Chrome film 12, 52 Aluminum neodymium film 13, 53, 105 Gate line 14, 110 Gate electrode 15, 54, 115 Gate terminal 16, 55, 120, 126 Gate insulating film 17, 125 Active pattern 18, 130 Ohmic contact pattern 19, 56, 135 Data line 20, 140 Source electrode 21, 145 Drain electrode 22, 58, 150 Data terminal 24 24, 60, 155 Second protective film 25, 61, 106, 160 First pad contact hole 26 , 62, 165, 175 Second pad contact hole 28, 68, 155, 180 Second protective film 29, 185 Contact hole 30, 69, 182 Unevenness 32, 72, 185, 190 Reflective electrode 33, 34, 66, 175 Data Pad electrode 50 Insulating substrate 51 Chromium films 61, 65, 170, 175 Gate pad electrodes 64, 162 Undercut 70 Barrier metal layer 102 First metal film 104 Second metal film 156 First contact hole 195 Thin film transistor

Claims (18)

A substrate including a display area and a pad area;
A first metal film formed on the substrate including a wiring layer terminal located in the pad region, and a second metal film laminated on the first metal film , the second metal made of aluminum or an aluminum alloy A wiring layer composed of a film ,
A first protective film having a pad contact hole formed on the substrate and the wiring layer and exposing the wiring layer terminal and the first metal film of the wiring layer part connected to the wiring layer terminal;
In a state in which the second metal film in the pad contact hole is not laminated on the first metal layer, the side walls and bottom surface of the pad contact hole, and the wiring is formed continuously over a portion of the first protective film A pad electrode made of a transparent conductive film, connected to the first metal film of a part of the wiring layer connected to the layer terminal and the wiring layer terminal;
A second protective film formed in a region excluding the pad region on the substrate;
A reflective electrode formed on the second protective film in the display region,
The reflective liquid crystal display device, wherein the pad contact hole is formed to extend to a lower portion of a second protective film in a boundary region between the display region and the pad region.   2. The reflective liquid crystal display device according to claim 1, wherein the pad electrode is formed to extend to a boundary region between the display region and the pad region along the pad contact hole.   A substrate including a display area and a pad area;
  A first metal film and a second metal film made of aluminum or an aluminum alloy are sequentially stacked on the substrate, and formed in a gate line extending in a first direction and the pad region. A gate wiring including a terminal connected to the end;
  A gate insulating film formed on the gate wiring and the substrate;
  A data line formed on the gate insulating layer and extending in a second direction perpendicular to the first direction; a data terminal formed in the pad region and connected to an end of the data line;
Including data wiring,
  A first pad contact hole is formed on the data line and the gate insulating film, and has a first pad contact hole through the gate insulating film and exposing the gate terminal and a portion of the gate metal connected to the gate terminal. 1 protective film,
  The gate terminal is formed continuously on a side wall and a bottom surface of the contact hole and a part of the first protective film in a state where the second metal film is not stacked on the first metal film in the pad contact hole. And a gate pad electrode made of a transparent conductive film connected to a first metal film of a part of a gate line connected to the gate terminal,
  A second protective film formed in a region excluding the pad region on the substrate;
  A reflective electrode formed on the second protective film in the display region,
  The reflective liquid crystal display device, wherein the first pad contact hole is formed to extend to a lower portion of a second protective film in a boundary region between the display region and the pad region.   4. The reflection type liquid crystal display device according to claim 3, wherein the gate pad electrode is formed to extend to a boundary region between the display region and the pad region along the first pad contact hole.   The data pad electrode further comprises a data pad electrode formed in the same layer as the gate pad electrode, and the data pad electrode is connected to the data terminal through a second pad contact hole formed with a gate insulating film and a first protective film on the data terminal. 4. The reflection type liquid crystal display device according to claim 3, wherein the reflection type liquid crystal display device is connected.   4. The reflective liquid crystal display device according to claim 3, wherein the first protective film is made of an inorganic material, and the second protective film is made of an organic material.   4. The reflective liquid crystal display device according to claim 3, wherein the second protective film has a contact hole exposing a part of the data line in the display area.   8. The reflective liquid crystal display device according to claim 7, wherein the reflective electrode is connected to a part of a data line in the display area through the contact hole.   A first metal film and a second metal film laminated thereon, comprising a wiring layer terminal located in the pad area on a substrate including a display area and a pad area, and made of aluminum or an aluminum alloy Forming a wiring layer composed of a second metal film;
  Forming a first protective film having a pad contact hole on the substrate and the wiring layer to expose the wiring layer terminal and a part of the wiring layer connected to the wiring layer terminal;
  Removing the second metal film in the pad contact hole by whole surface etching;
  The wiring layer terminal and the wiring layer terminal connected to the wiring layer terminal by continuously forming a pad electrode made of a transparent conductive film on the side wall and bottom surface of the pad contact hole and on a part of the first protective film. Connecting to a portion of the first metal film;
  Forming a second protective film in a region on the substrate excluding the pad region;
  Forming a reflective electrode on the second protective film in the display region. A method for manufacturing a reflective liquid crystal display device, comprising:   Forming the first protective layer comprises:
  Forming a first protective film on the substrate and the wiring layer;
  Partially etching the first protective film to form a pad contact hole that exposes the wiring layer terminal and a second metal film of a portion of the wiring layer connected to the wiring layer terminal;
  10. The method of manufacturing a reflective liquid crystal display device according to claim 9, further comprising: etching the entire surface of the exposed second metal film to expose the first metal film below the second metal film.   10. The method of manufacturing a reflective liquid crystal display device according to claim 9, wherein the pad electrode is formed along the pad contact hole up to a boundary region between the display region and the pad region.   A first metal film and a second metal film stacked on the first metal film on the substrate including the display area and the pad area, the second metal film made of aluminum or an aluminum alloy, and arranged in the first direction. Forming a gate line including a gate terminal formed on the extended gate line and the pad region and connected to an end of the gate line;
  Forming a gate insulating film on the gate wiring and the substrate;
  A data line is formed on the gate insulating film, the data line including a data line extending in a second direction perpendicular to the first direction and the pad region and connected to an end of the data line. Stages,
  A first protection having a first pad contact hole on the data line and the gate insulating film to expose the gate terminal and a first metal film of a part of the gate line connected to the gate terminal through the gate insulating film. Forming a film;
  Removing the second metal film in the pad contact hole by whole surface etching;
  A gate line connected to the gate terminal and the gate terminal by continuously forming a gate pad electrode made of a transparent conductive film on a side wall and a bottom surface of the first pad contact hole and a part of the first protective film Connecting with a portion of the first metal film;
  Forming a second protective film formed in a region excluding the pad region on the substrate;
  Forming a reflective electrode on the second protective film in the display region. A method for manufacturing a reflective liquid crystal display device, comprising:   Forming the first protective layer comprises:
  Forming a first protective layer on the substrate and the data wiring;
  Partially etching the first passivation layer and the gate insulating layer to form a first pad contact hole exposing the second metal layer of the gate line connected to the gate terminal and the gate terminal;
  Etching the entire surface of the exposed second metal film to expose the first metal film underneath;
  The method of manufacturing a reflective liquid crystal display device according to claim 12, comprising:   14. The method according to claim 13, wherein in the step of forming the first pad contact hole, a second pad contact hole exposing the data terminal is formed together.   15. The method of claim 14, wherein in forming the gate pad electrode, a data pad electrode connected to the data terminal through the second pad contact hole is formed together.   13. The method of manufacturing a reflective liquid crystal display device according to claim 12, wherein the gate pad electrode is formed up to a boundary region between the display region and the pad region along the first pad contact hole.   13. The method of manufacturing a reflective liquid crystal display device according to claim 12, wherein the first protective film is formed of an inorganic material, and the second protective film is formed of an organic material.   13. The method of manufacturing a reflective liquid crystal display device according to claim 12, wherein in the step of forming the second protective film, a contact hole for exposing a part of the data line in the display region is formed.

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